HL, let's see if someone throws me a little hand. I have problems with the revolutions of my Seat Ibiza TDI 1.9 ATD engine. Normally when I started the needle marks me 950 and then after a while I accelerates the engine a little and marks me all the time 1,000rpm and I don't know what the problem will be.
Did you see the correct operation of the Lamda probe? It happened to me once the Lamda or oxygen sensor probe was bad and that's why I accelerated at times.
Also check the operation of IAC (Conrollentí), these derepentes are stuck.